AACR: Germany's small NK cell player Affimed makes a big splash with early lymphoma data
German small-cap Affimed has long been highlighted as a potential Cinderella story, winning milestone-rich deals with Genentech and Roivant. And on Friday the biotech continued its NK cell march, presenting the first look at in-human data ahead of this weekend’s AACR conference.
Researchers saw significant disease reduction in all four lymphoma patients dosed with Affimed’s experimental off-the-shelf NK cell therapy, with two registering complete responses as of the March 31 data cutoff, the company announced. All of the patients had been heavily pretreated — with a range of four to 14 lines of prior therapy — and there were no signs of cytokine release syndrome, toxicity or graft-versus-host disease.
Three of the four patients received the lowest dose, and enrollment of the second dose cohort is continuing in the MD Anderson-sponsored trial. All of the patients had been diagnosed with recurrent/refractory CD30-positive lymphomas.
News of the data sent Affimed $AFMD shares up about 23% when the market opened Friday morning.
The therapy itself contains what Affimed calls a bispecific “innate cell engager” known as AFM13, and there are two steps to the treatment process for this population, CMO Andreas Harstrick told Endpoints News. First, Affimed attaches AFM13 to NK cells derived from healthy donors and administers these to the patients. Then, the patients received three weekly IV infusions of AFM13 by itself.
These steps are necessary because the patients have weakened innate immune systems and very low counts of NK cells, Harstrick said. If one were to give either NK cells or AFM13 by themselves in this group of patients, the result would be a therapy with “very little efficacy” compared to combo, he said.
Affimed had to work through several challenges to get AFM13 to work as intended, Harstrick added. Chief among those was developing a way for the compound to tightly bind to both the NK cells and the CD30 tumor antigens, so that it wouldn’t be “washed off” when circulating the bloodstream.
The biotech solved that issue not only through its tech that provides tighter interactions for the NK cell binding site, but by prepping the NK cells with AFM13 in the first step of the treatment process, outside the patient. With Friday’s data, Harstrick says it’s clear the NK cells are being delivered to the right places.
“When you infuse these NK cells back to the patient, all of these NK cells will carry AFM13 on their surface, and with the other part of AFM13 we are binding to CD30 on the tumor cells,” Harstrick told Endpoints. “So basically we train these NK cells to recognize the tumor with this very simple method of co-culturing and pre-incubation.”
As the dose escalating cohorts continue, Affimed will increase the specially prepared NK cell count given to the patients. The weekly AFM13 doses post-NK cell administration will remain the same.
There are different cancers where AFM13 can potentially be used on its own in patients that have higher NK cell counts, he added. One of these areas is T cell lymphomas, where Affimed is currently enrolling a registrational Phase II trial.
Some analysts looked favorably on Friday’s news, with Jefferies’ Maury Raycroft appearing encouraged. In a note to investors early Friday morning, Raycroft wrote that even though the data are early, they demonstrate the therapy is active and support the proof of concept.
Affimed appears ready to prove its deal with Genentech back in 2018 will end up a big winner, when the biotech earned $96 million upfront and was promised up to $5 billion in milestones to team up on its natural killer cell platform for cancer. Then last November, Affimed signed a licensing deal with Roivant for a different preclinical program, AFM32.